1. Technical Field
This invention relates generally to wireless receivers and more particularly to gain control within a wireless receiver.
2. Description of Related Art
Handheld digital audio systems are becoming very popular. Such systems include digital audio players/recorders that record and subsequently playback MP3 files, WMA files, et cetera. Such digital audio players/recorders may also be used as digital dictaphones and file transfer devices. Further expansion of digital audio players/recorders includes providing a frequency modulation (“FM”) radio receiver such that the device offers FM radio reception.
A typical digital. FM receiver receives a continuous time radio signal, amplifies the continuous time radio signal, down converts the continuous time radio signal to a baseband/low IF signal, and then filters the signal, all in the analog domain. Then, the digital FM receiver samples the analog baseband/low IF signal and digitally processes the FM signal. Such digital processing includes digital filtering and audio content extraction. In order to achieve maximum fidelity from the digitized signal, a magnitude of the digitized signal should be as near 100% saturation as possible of the data width of a circuit that performs the digital processing, e.g., a Digital Signal Processor. The magnitude of the analog FM signal, however, varies over time between a relatively strong signal and a relatively week signal. The time-varying magnitude of the FM continuous time radio signal directly relates to the digitized signal, which diminishes the ability of the digital circuitry to produce an accurate audio signal. There exists a need to solve these signal processing problems.